This verse sits inside the father's lecture on wisdom and the neighbor, Proverbs 3:21–35.
Quick answer
Do not live braced for catastrophe. Sudden terror and the trouble the wicked cause are real, the verse says "when it comes," not "if", but the wise are not required to fear them in advance.
Read the whole unit
The father's lecture on wisdom and the neighbor moves in three sweeps. First, security (vv. 21–26): keep sound wisdom in view and the results are bodily and immediate, safe steps, unafraid nights, sweet sleep, because "the LORD will be your confidence." Second, the neighbor (vv. 27–31): five consecutive "do nots" that bring wisdom down from the cosmos of the preceding poem to the person next door. Do not withhold good that is owed, do not delay it until tomorrow, do not plot against the neighbor who trusts you, do not pick fights, and do not envy the violent man who seems to be winning. Third, the reasons (vv. 32–35): four verses that ground neighbor-ethics in the LORD's own stances, His abomination and His intimacy, His curse and His blessing, His scorn and His grace, and the divergent inheritances of the wise and the foolish. Some scholars divide the passage at v. 27, treating the neighbor commands as their own unit; the flow of thought holds together as one lecture, since the "do nots" rest directly on the security just described (a person confident in the LORD can afford to be generous and unenvious) and the closing verses supply the reasons for both halves. This entry set treats 3:21–35 as one lecture and notes the boundary question honestly here, once.
What this verse contributes
This verse distinguishes danger from dread: it does not promise trouble will never arrive, its own second line concedes the arrival, but it forbids the pre-payment of fear. Trouble taxes you once when it comes; dread taxes you daily whether it comes or not. The command would be cruel alone, since no one simply decides to stop fearing; it does not stand alone. The next verse supplies the only footing such fearlessness has.
Related: Psalm 112:7 · Matthew 6:34
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.